Syd'Quan Thompson recently got a tattoo on the inside of his left forearm, near his wrist. It reflects Thompson's personality, in many ways, because he's soft-spoken, introspective and the leader/conscience of Cal's defense.

So the tattoo also is low-key and unassuming: "The biggest mistake in life is being afraid to make a mistake."

The senior occasionally glanced at the tattoo during training camp, and he plans to do the same in Saturday night's season opener against Maryland. It's an instructive reminder for one of the top cornerbacks in college football, because he plays a position prone to imperfection - and one where mistakes stand out.

"I look at it whenever I miss a play or something, just so I don't feel down," Thompson said of the tattoo. "You're lonely out there on the corner. ... Whenever times are rough, it's something to keep me going."

Thompson, a first-team, all-Pac-10 selection last season, returns as the headliner on this Bears defense. He has started 39 consecutive games, a streak starting with his rocky college debut against Tennessee - launching a career that has come full circle, with many opponents now reluctant to even throw his way.

Thompson frequently gets his hands on the ball when quarterbacks do test him. He intercepted four passes last year, broke up 14 others and usually convinced those quarterbacks not to bother.

Still, playing cornerback means occasionally watching receivers pluck passes out of the air and prance into the end zone. It happened against Thompson in that 2006 game at Tennessee, where he surrendered three big plays to Vols wideout Robert Meacham. It also happened in last year's loss at Maryland, where Darrius Heyward-Bey made a TD catch over Thompson.

But it does not happen often, mostly because Thompson's skills stretch beyond his striking quickness and terrific instincts. Cal teammates and coaches speak about him as if he's the surrogate defensive coordinator (no offense to Bob Gregory), a roving instructor on the field.

"Syd is the rock of the defense," safety Brett Johnson said. "If you have a question about almost anything on anyone's position, he's likely to know the answer."

Thompson arrived at Cal in 2005, not entirely sure if he would play cornerback or wide receiver. He spent his first week of practice at receiver before moving to defense, where he felt like he had a job on every down.

Not coincidentally, he admired Deion Sanders and Charles Woodson while growing up in Sacramento; Thompson also is an accomplished punt returner. And though he lacks the flamboyance of Sanders or Woodson, he shares the vision needed to become a great cover/return man.

"Some people can just see what's in front of them, but Syd can kind of see everything," defensive backs coach Al Simmons said. "He can have vision on a lineman but still see a receiver, or he can have vision on a receiver and still see the quarterback."

The quarterback can see Thompson simply by finding the Cal player with the long dreadlocks bouncing off his back. Thompson wore his hair in cornrows during his first year in Berkeley, then contemplated cutting it short. He decided he had invested too much time in his hair for that, so he twisted it into dreadlocks.

He spoke sheepishly about his hair, until being told some 9-year-old fans think it's cool.

"Hopefully, we can get everyone out here with some dread wigs," Thompson said, smiling.

Tedford called it a "very close competition" between D'Amato and Tavecchio.

"Vince has been a little more consistent," Tedford said. "We feel like he has great range. Either one of them would do a really nice job, but Vince just kind of edged him out for the spot."

Briefly: Cornerback Darian Hagan missed Wednesday's practice; Tedford said Hagan was resting a sore knee and will play against Maryland. ... Cal officials expect a crowd between 55,000 and 60,000 on Saturday night.